А) (a-3b)+(5a-3b)-2a = a-3b+5a--3b -2a= 4a - 6b = 2(2a-3b)
б)4x(x+5)-5x(2x+3)= 4x^2 + 20x - -10x^2 - 15x = 5x - 6x^2 = x(5-6x)
в) (x-2)(x^3+3)-x^3 = x^4 - 2x^3+3x-
- 6 -x^3 = x^4 - 3x^3 + 3x - 6 = =x^3(x-3) + 3(x - 2)г)7(3y-2)-4(5y-4)=21y-14-20y+16=
= y + 6